For the energy production, the amount of biomass used by a specific power plant is limited by the quantity at which the high grade biomass can be delivered at a feasi­ble cost. The charges associated with the given amount of woody biomass were determined by the costs of stumpage, regression, harvesting, chipping and transpor­tation. For any organization, the quantity of biomass available at a given cost is also influenced by the transportation distance to some extent (Goerndt et al. 2013). The following subsections describe the ways and conventions used for the estima­tion of the woody biomass available for the power plants during energy production process. It also mean to provide the cumulative information regarding the costs associated with the purchase of woody biomass and other associated charges including delivery in the successive larger procurement and consumption areas.

14.7.1 Techniques to Improve the Interface Adhesion

The biggest challenge in developing of material composites based on natural fibers is the incompatibility between the hydrophilic fibers and the hydrophobic matrix. This incompatibility leads to a poor homogenization between fibers and the

polymer chains (Nazrul et al. 2010); as a result, a poor adhesion between both com­pounds is often seen (Pickering et al. 2007; Ku et al. 2011). Most studies refer to the modification of the interface of natural fibers or polymer matrix, to ensure compat­ibility between the fiber and the matrix (Huu Nam et al. 2011; Arrakhiz et al. 2012a). The treatment parameters used is a factor that influences the properties and characteristics of the result composites. Therefore, appropriate treatment tech­niques and parameters must be carefully selected to produce an optimal composite product. These techniques can be divided into two categories: physical and chemi­cal methods.

The physical treatments do not alter the chemical composition of the cellulose fiber and they are expensive (Belgacem et al. 1995). Stretching, calendering, ther­mal treatments are considered as an example of physical treatment (Belgacem et al. 1996; Liu et al. 1998). Other types of physical treatment are also found in the litera­ture as the electric discharge (corona, cold plasma). For example the electrical discharge treatment can modify the fiber surface from hydrophilic to hydrophobic by changing the surface energy (Belgacem and Gandini 2005; Kato et al. 1999).

The use of chemical treatments is for removing the non-cellulosic components in the fiber surface or for adding functional groups to increase connection with

polymer chains. Several chemical techniques were considered to improve the adhesion interfacial such as, grafting compatibilizer groups, addition of a coupling agent or cleaning the fiber’s surface. The alkali treatment is one of the standard chemical treatments using sodium hydroxide to remove amorphous and non-cellu — losic components from the fibers’ surface. The estherification or etherification of the hydroxyl groups found on the fibers’ surface is a possible technique to graft a func­tional group (Arrakhiz et al. 2012a). The use of maleic anhydride modified polypro­pylene (MAPP) as a coupling agent is another pathway to enhance the interface adhesion between fibers and matrix (Arrakhiz et al. 2012c). Fiber surface treatment may also increase the strength of the fiber; reduce the water absorption and surface tension between fiber and matrix.

The use of maleic anhydride grafted polypropylene; SEBS-g-MA as compatibil — izer between fibers and matrix improves the water resistance of fibers and enhance the wettability of fibers in the polymer matrix, also the use of SEBS-g-MA create a strong ester bonds between polymer and hydroxyl groups of fibers. Figure 14.9 shows the FTIR curves of PP/Pine cone composites with and without coupling agent. The peaks at 1,703, 1,652, and 1,560 cm-1 were observed after addition of compatibilizers, these peaks are the main characteristic peaks of ester bonds formed. These formed ester bonds between matrix and hydroxyl groups of fibers enhance the thermal and mechanical properties of composites.

SEM micrographs analysis of fracture surfaces of composites with coupling agent (Fig. 14.10) confirm that the addition of coupling agent improves the interface adhesion between doum fibers by absence of decohesion zones (pull out fibers), and reduction of the fiber/fiber contact.

The comparative thermal analysis between the composites with compatibilizer and without compatibilizer is found in the literature Arrakhiz et al. (2012a, b, c). Table 14.1 illustrates the comparative thermal analysis of Doum and Hemp fibers and their composites with and without compatibilizer. It was seen that the compos­ites compatibilized exhibit a higher temperature degradation than composites without compatibilizer.

The improvement in the fiber-matrix adhesion enhances the mechanical prop­erties of composites (Elkhaoulani et al. 2013). Figure 14.11 shows the compara­tive tensile properties of the fibers as Pine cone, hemp and Doum. Addition of

fibers increases Young’s modulus, until it reached one maximum value at 25 wt.% (for all composites). On the other hand, the tensile strength of various composites compatibilized is stabilized at a high value, except PP/hemp which shows a slight decrease. The tensile strength properties are higher in the composites compatibil­ized than composites without compatibilizer, this is due to the good interfacial adhesion (fibers/matrix). The maleic anhydride molecules grafted to PP construct a strong ester bonds with the hydroxyl groups (OH) present on the fibers’ surface (Elkhaoulani et al. 2013).

A good dispersion and interfacial adhesion between the matrix and fibers are both critical factors for the resulting composites to achieve improved mechanical properties. Chemical treatment of the fibers’ surface was used to improve interfacial adhesion in the composite. Table 14.2 illustrates influence of chemical treatments and fictionaliza — tion on two composite systems with different fibers (Alfa and Coir), at 20 wt.%, and thermoplastics matrix (PP and HDPE). The chemical modifications used in this work, namely NaOH, etherification (C12 (Dodecane bromide)), Estherification (Palmitic acid N-succinimidyl), and silane (3-(trimethoxysilyl) propylamine) exhibit a different inter­action mechanism with both fibers and polymer matrices.

The results show that chemical treatments improve the mechanical thermal pro­prieties of fibers, leading to improvement in properties of composites reinforced with these treated fibers. Alkaline treatment shows higher values in terms of young’s modulus, also composites with fibers fictionalized with silane and C12 shows a sig­nificant tensile modulus when compared to raw fibers reinforced polymer.

The utilization of renewable and cheaper precursors to prepare activated carbon produces useful and economically feasible adsorbent but also contributes towards minimizing the solid wastes. The preparation method can be optimized to deter­mine the effect of the main parameters associated with the process are: Impregnation ratio, activation temperature, acid concentration, activation time, the precursor materials nature, the activation type (chemical and physical activa­tion), and pyrolysis temperature, all these affect the properties of the resulting activated carbon (Girgis and El-Hendawy 2002; Haimour and Emeish 2006; Diao et al. 2002).

The processing conditions are generally expressed in terms of some properties, among which: surface area, cation-exchange capacity (CEC), phenol and methylene blue, bulk density and adsorption efficiency towards iodine are frequently consid­ered (Vernersson et al. 2002; Yang and Lua 2006; Haimour and Emeish 2006). However, methylene blue is the most accepted probe molecules for the determina­tion of the ability of sorbent for the removal of large molecules whereas the iodine number shows indication on microporosity and consequently on the specific surface area of the sorbent materials (Baccar et al. 2010). Therefore, to determine the most important factor and their regions of interest it is essential to study these factors and their effects on the production of activated catalyst.

Experimental design technique is an important tool which provides statistical models in understanding the interactions among the parameters that have been opti­mized (Alam et al. 2007). The major benefit of using Response Surface Methodology (RSM) is to reduce the number of experimental trials required to evaluate several parameters and their interactions (Lee et al. 2000). RSM is a collection of statistical and mathematical techniques useful for developing, improving and optimizing pro­cesses. RSM involves three main stages: (1) design and experiments, (2) response surface modeling through regression, (3) optimization (Myers and Montgomery 1995). Based on this central composite design (CCD), quadratic models were devel­oped. The analysis of variance (ANOVA) on each experimental design response was recognized from them (Ahmad and Hameed 2010). Previously RSM was applied for the preparation of activated carbons using precursors such as Luscar char (Azargohar and Dalai 2005), Turkish lignite (Karacan et al. 2007), and olive-waste cakes (Bagaoui et al. 2001).

J. curcas owing to its remarkable features appears to be a suitable valuable option to meet energy demands world. Low technology inputs are requirements during cultivation step, where most of the management actions are done manually (pruning and harvesting, mainly), to harness oil reduces the investment required to generate a unit quantity of biofuels.

Multiple energy carriers of Jatropha plants and oil expelled from its seeds are not only useful in mitigating the environmental pollution but also support for employ­ment generation and entrepreneurship development. Apart from Jatropha use as potential energy crop, industrial application and soil conservation measures can also promote its cultivation on the barren and unused land. As energy crop, blending with petro-diesel and proper processing has already demonstrated its use as an alter­native fuel in motive and stationary diesel engines. Proper commercialization and utilization of by-products of biodiesel such as press-cake and glycerine oil cake can make Jatropha cultivation and oil production economically more feasible.

A better overall efficient development of J. curcas production system can be achieved, if knowledge gulf regarding fundamental agronomic characteristics, employment of best cultivation and management practices, the improvement of energy carriers and processing of oil protocols and the input/output balances at all these stages are addressed into. A deep analysis of cultivation processes will help in understanding intercropping and monoculture growth variables as well as looking for sustainability indicators in these two production systems.

A better in-depth understanding of the eco-physiology of the plant is required so to gain insight into its nutrient requirements for maximum net primary productivity and oil production, nutrient cycling, impact on biota of soil (Achten et al. 2008), plant-soil relationship, and foliar nutrient content of Jatropha (Daey Ouwens et al. 2007; Chaudhary et al. 2008) which is essential for domestication of the plant, its water use efficiencies, its potential and actual energy.

Apart from these mentioned concern, also environmental impact assessments have not been carried out exhaustively yet (Achten et al. 2008). Impacts on soil structure and its water-holding capacity, organic content and soil biological activity needs detailed investigation as well. Research for understanding plant energy efficiency under different agro-climatic condition and to improve its yield needs to be carried out (Daey Ouwens et al. 2007).

Jatropha bioenergy development has many potential benefits although having some negative impacts also. Development of this sector calls for execution of well balanced policies which can reduce the negative effects and maximize positive ones. Of positive effects some are:

1. Agricultural output diversification

2. Higher income for farmers

3. Poverty reduction

4. Rural development stimulation,

5. Employment in rural areas

6. Infrastructure development

7. Increased investment in land rehabilitation

8. Lower GHG emissions

9. Generation of new revenues from agricultural residues, wood use, and from carbon credits

On the other hand, some potential negative effects are:

1. Replacement of subsistence farmland with energy crops will result in reduction in local food availability.

2. Increase in deforestation to meet land demand for energy crops will lead to forest ecosystems degradation and decrease in biodiversity as well.

3. Degradation of soil fertility and quality due to intensive cultivation of bioenergy crops.

4. Pollutants as well as GHG emissions will register an increase.

5. Modifications to requirements for vehicles and fuel infrastructure.

Nonetheless, with the current emphasis on alternative renewable fuels due to the soaring fossil energy prices as their reserves continue to dwindle and the per­spective on global climate change, the potential role of Jatropha to meet energy services of world will warrant it beyond doubt to be one of the energy plants of future.

NFC as eco-friendly materials, have been emerged as an alternative to the tradi­tional glass/carbon-reinforced polymer composites. They are attractive materials for different applications like packaging, furniture, and automotive industries. Such materials have several advantages like, the low cost, acceptable mechanical proper­ties, good thermal and acoustic insulating properties, availability, CO2 sequestration enhanced energy recovery, etc. The properties and performance of the final natural fiber composites depend on the properties of both the matrix and filler as well as their interfacial bonding.

Both physical and mechanical treatment processes were performed on the cellulosic fibers to enhance the interfacial bonding characteristics of the natural fiber composites. Different factors and criteria can affect the performance of the produced natural fiber composites. Some of these criteria affect the selection of the composite constituents (matrix and fillers), whereas others can determine the final performance of the produced product of such materials. Wide range of physical, biological, mechanical, environmental as well as economic properties of the poly­mer composite have to be investigated to optimize and widen their potential applications.

The petroleum derived thermoplastics and thermosets are widely used for pro­ducing different natural fiber composites oriented for various industrial applica­tions. The potential and competitiveness of the palm fiber was proved for different industrial applications particularly the automotive ones. It can be considered that date palm fiber is one of the most available natural fiber types all over the word. It can be utilized with different polymer matrices to produce satisfactorily strong composites. The effect of the chemical treatment of the date palm fiber had been proven to increase its final mechanical properties as well as its reinforced polymer composites.

1.5 Conclusions

The NFRPC became recently a valuable type of materials due to their desirable eco­friendly characteristics. Adopting the natural wastes and resources in finding alter­native low cost materials can enhance the industrial sustainability as well as reducing the environmental pollution. Biodegradability, low cost, low relative density, and the high specific strength characteristics are the main added value steps of the natu­ral fiber composites. Widening the application of such materials can contribute to the human living standards as well as the green environmental indices. Many poten­tial natural fiber types are still undiscovered due to the improper evaluations of such fibers. Date palm fiber is one of the most competitive fiber types for producing natu­ral composites. Several studies had demonstrated its capability to produce different composites with various thermo plastics and thermoset polymers. Proper fiber treat­ment can enhance the role of date palm fiber in supporting the natural composites with more desirable characteristics to contribute the sustainable industrial applica­tions. Further research is required to improve the natural fiber performance and to overcome their drawbacks like the moisture absorption, inadequate toughness, and reduced long-term stability for outdoor applications.

Acknowledgment The authors extend their appreciation to the Deanship of Scientific Research at King Saud University for funding this work through research group no RGP-VPP-133.

1. As per the “End-of-Life-Vehicle Regulation” by the European parliament, the natural fibers like abaca will be used in designing and manufacturing of car com­ponents which will enable their safe disposal and recyclability at the end of their life. Moreover, research is being conducted to develop needle punched abaca fabric for possible use in the production of padding and backing for automotive industry.

2. Abaca fiber has a great potential in ship building, aeronautics, and construction of high-rise buildings.

3. Compared to cordage made of synthetic fibers, the abaca fibers are biodegrad­able and therefore can be dumped without any environmental hazard. Moreover, the poor reflecting ability of abaca ropes makes them suitable for use in American movie-making industry as they do not reflect on exposure to klieg lights.

4. The use of abaca fibers in preparation of sausage casings has a great potential due to their inability to dissolve in boiling water besides being free from any health hazard (if eaten mistakenly)

5. Abaca fibers offer a good and easily available substitute for wood pulp, thereby reducing the pressure on the conventional sources of pulp-yielding plants. A good example is provided by Japan where the Japanese currency (¥10,000, 500, and 1,000) has been found to contain about 60 % abaca components. Similarly there are reports from China where a huge increase in demand for abaca fibers is expected to meet the requirements for recycling waste paper. Similar example is provided by the European company “the PH Glatfelter” who has produced the disposable K-cups made of special filter paper containing 100 % abaca fiber.

6. Abaca fiber also has great potential in the production of world-class furniture like sofas, tables, chairs, beds, etc.

7. The production of products like abaca soap or lotion with anti-aging or therapeu­tic properties will also revolutionize the cosmetic industry.

8. It also offers great potential for textile industry as blending of abaca fibers with other natural fibers like silk can be used to produce fabrics of excellent quality, e. g., the manufacturing of denim by Asiatex (The Asia Textile Mills, Inc.) in Calamba City by bending of abaca (40 %) and polyester (60 %). Other fabrics like shirts, blouses have also been developed and research is being conducted to pro­duce fabrics of extraordinary qualities like antimicrobial and “stay cool and fresh.”

9. Abaca-reinforced composites have a good potential for use in automotive plastics.

Kapok fiber contains the pectin and wax substances that contribute to its hydro­phobic-oleophilic characteristic. On the glass slide coated with kapok extract, the diesel drop and water drop will show a different spreading radius and contact angle. The diesel drop can spread out rapidly, and in contrast, the water drop cannot spread out on the glass slide. As a result, a large spreading radius and small contact angle are observed for diesel drop, whereas a large contact angle is visualized for water drop, demonstrating that the oil is a wetting liquid for kapok fiber and the water is a non-wetting liquid for kapok fiber (Lim and Huang 2007). The static and dynamic contact angle of kapok fibers with different kinds of liquids such as vegetable oil, used oil, and engine oil is also investigated. It is found that kapok fiber is an excel­lent oleophilic and hydrophobic fiber with the contact angle of kapok fiber to water of 139.55o, but is less than 60o to various kinds of oil. The contact angle of kapok to water is constant as time flies. All the oil liquids on the kapok fibers have the quick spread rates, and the spread curves are similar though the spread rates varied with viscosity and surface tension of the liquids (Sun et al. 2011). This hydrophobic — oleophilic characteristic can be tuned by solvent treatments. Our study reveals that for untreated and NaClO2-treated kapok fiber, different wetting phenomenon can be observed using water drops, with a large contact angle of 116o and a large spreading

radius for untreated and NaClO2-treated kapok fiber, respectively (Fig. 6.2) (Wang et al. 2012b). Here, another observation should also be mentioned. Before and after collecting the oils from water, the kapok fiber may float steadily on the water sur­face due to its light density and hydrophobic-oleophilic properties, a useful charac­teristic for oil spills cleanup. In addition to the thin hydrophobic plant wax layer covered on the surface of kapok fiber, the hydrophobic-oleophilic characteristic is also related to its micro-nano-binary structure (Zhang et al. 2013).

One third of the total primary energy is contributed by straw in sugarcane as a crop. Sugarcane also possesses some characteristics which are very similar to widely used bagasse. This makes it a very good fuel to bagasse supplement. It can contrib­ute to surplus power generation in the mills. For the second generation production of biofuels, straw can be efficiently used. An excellent opportunity is provided in Brazil in order to increase the fast implementation of management system of green cane to increase sugarcane energy performance, sustainability of the production of ethanol, as well as the economics. But its use is incipient, still. This is due to lack in the long-term experience with collection and use of straw along with the uncertain­ties in the processing, storage, and collection costs (Leal et al. 2013).

The benefits imparted by agronomic characteristics are pretty clear, but the quan­tification is difficult although their magnitude is analyzed in different situations. The minimum amount for the assurance of ground protection against erosion has not been estimated. A significant difference is contributed between burned cane, which is in bare soil and unburned cane, with straw mulch on the ground in the water and soil losses. Literature revealed a consistent increase concerning the con­tent of soil carbon in the management of green cane with all straw left in the fields in comparison with burned systems of cane. A wide variation has also been shown in the results as it depends on climate and soil characteristics as well as the history of land use.

It has been noted that straw blanket imparts positive as well as negative impacts on the biota. Positive effects on macrofauna in the soil mainly include ants and worms, whereas the negative one includes increase in population of pests. The effect of inhibition of weed by straw mulch has also been confirmed by several authors for some of the species and has been found neutral for others. This data helped in gath­ering information about the magnitude of different impacts imparted by straw mulch left on the ground after harvesting the unburned sugarcane. This helped in assess­ment of optimum straw that should be left in the field to take advantage of the agro­nomic and industrial benefits. There are many variables that affect various benefits that were included in the evaluation. These variables include soil and climate char­acteristics, local topography, varieties of sugarcane and agricultural practices, etc.

At this time it is not possible to define proper amount of straw that should be left on the ground.

Best approach would be initial concentration on the erosion of soil and dynamics of soil carbon. These are associated with both economic and environmental benefits. Economic benefits include fertility of soil, yield of the crop, and cost of the produc­tion, whereas preservation of natural resource, crop sustainability, and sequestration of carbon are involved in the environmental benefits. Finally, it is significant to pin point the viability of integration of technologies of second generation in future. This involves conventional distillery of sugarcane which increases the yield of biofuel per unit area cropped and the efficiency of energy. This requires the use of straw fraction that results from unburned harvesting of cane.

The key ingredient to initiate photosynthesis is light as it is involved in the conver­sion of carbon dioxide to carbohydrates. As compared to higher plants, algae require relatively low intensity of light for proper development. Solar waves are

the primary source of light. Only 43-45 % of the total solar radiations are involved in commencement of photosynthesis. These radiations are termed as PAR or Photosynthetically Active Radiation. About 27 % of PAR is converted to carbohy­drates. The rate of biomass growth can be established by considering the following relation:

P = aE. l

where P is the rate of production of dry algae and is measured in g/m2/day, E is the efficiency of photosynthesis, I denotes light energy in kcal/m2/day, and the symbol a represents the conversion coefficient (g/kcal).

The light source in the cultivation system can be either natural, artificial, or com­bination of different light sources. The cheapest source is the solar energy, which is utilized in open pond systems, which require a large area for construction and have a higher contamination risk. In closed systems, fiber optics and solar concentrators can be used to maximize the effect of sunlight. As compared to fluorescent lamps, LED lights are shown to be more economically stable.

13.2.1.4 Nitrogen

Being the main constructing element of proteins and nucleic acids, nitrogen plays a significant role in algal metabolism.

13.2.1.5 Phosphorous

This element is used in the form of phosphates because if it is present in any other state, it may become unavailable to the algae due to its ability to combine with other metallic ions, which results in precipitation.

13.2.1.6 Additional Nutrients

Apart from the above-mentioned nutrients, trace amount of vitamins and metals like sodium, calcium, magnesium, manganese, zinc, copper, iron, and molybdenum are also required for efficient growth of algal culture.

13.2.1.7 Space

Unlike other organisms, algae are very versatile and do not require arable land for productive growth. They can be cultivated in ponds, water bodies, and even reactors. Issue of appropriate space is not a concern and does not put a strain on the budget or available resources.

The energy production through sugarcane straw involves the liquid, gaseous, and solid fuel production. Ethanol fuel is the most important that reduces our dependence on oil. Sugarcane straw is a suitable material for the ethanol fuel production because of its higher cellulose and hemicellulose content, which can be hydrolyzed, for instance, into fermentable sugars, and its other characteristics. The processes involved in bioethanol production are appropriate pretreatment, straw hydrolysis, conversion of the cell walls to simple sugars, anaerobic fermentation to convert the sugars to ethanol, and finally distillation. Pretreatment of straw is estimated for bioethanol production to account for 33 % of the total cost of bioethanol production. Appropriate pretreatment selection technique is the major challenge for the development which is economically sustain­able for bioethanol production technology from straw.